code: def setUpClass(cls):
      init_default_scope("mmdet")
      cls.cfg = dict(
          type="AppearanceFreeLink",
          checkpoint="",
          temporal_threshold=(0, 30),
          spatial_threshold=75,
          confidence_threshold=0.95,
      )
  
file_path: mmdetection/tests/test_models/test_task_modules/test_track/test_aflink.py
imports: from unittest import TestCase
  import numpy
  from mmengine.registry import init_default_scope
  from torch import nn
  from mmdet.registry import TASK_UTILS
label_desc: Use image node_id 1 for calling the TestAppearanceFreeLink obj's underlying member method code with example usage: obj.setUpClass(cls) without return types